Summary: Mary worshipped Jesus as the Lamb of God through extravagant surrender of all that she possessed.
“When Jesus was at Bethany in the house of Simon the leper, a woman came up to him with an alabaster flask of very expensive ointment, and she poured it on his head as he reclined at table. And when the disciples saw it, they were indignant, saying, ‘Why this waste? For this could have been sold for a large sum and given to the poor.’ But Jesus, aware of this, said to them, ‘Why do you trouble the woman? For she has done a beautiful thing to me. For you always have the poor with you, but you will not always have me. In pouring this ointment on my body, she has done it to prepare me for burial. Truly, I say to you, wherever this gospel is proclaimed in the whole world, what she has done will also be told in memory of her.’” 
It was only hours until the Master would be crucified. He had told His disciples repeatedly that His life would be taken from Him, and they still did not understand. Perhaps they could be forgiven for failing to understand the first references—they were somewhat vague. Jesus said, “Just as Jonah was three days and three nights in the belly of the great fish, so will the Son of Man be three days and three nights in the heart of the earth” [MATTHEW 12:40]. However, Jesus became increasingly specific as the time of His passion drew near.
Nevertheless, the Master had attempted to instruct the disciples from earliest days. Peter had just made his great confession concerning Jesus [MATTHEW 16:13-20]. It was assuredly a powerful insight concerning Jesus that Peter revealed through his confession. In fact, the Master commended him for his sensitivity to the Spirit of God. However, take careful note of the verses that follow. “From that time Jesus began to show his disciples that he must go to Jerusalem and suffer many things from the elders and chief priests and scribes, and be killed, and on the third day be raised. And Peter took him aside and began to rebuke him, saying, ‘Far be it from you, Lord! This shall never happen to you.’ But he turned and said to Peter, ‘Get behind me, Satan! You are a hindrance to me. For you are not setting your mind on the things of God, but on the things of man’” [MATTHEW 16:21-23; see also MARK 8:31-33]. When it became apparent that the disciples were convinced of Jesus’ Person, He began immediately to teach them of His sacrifice. Just as precipitously, Peter and the other disciples attempted to dissuade Him from offering Himself as a sacrifice, only to earn His stern rebuke.
Shortly after this first clear statement of His sacrifice, Jesus again spoke of His pending death. Again, the disciples could not comprehend what He was saying. “As they were gathering in Galilee, Jesus said to [His disciples], ‘The Son of Man is about to be delivered into the hands of men, and they will kill him, and he will be raised on the third day’” [MATTHEW 17:22, 23]. The text continues by noting that, “they were greatly distressed.” They didn’t understand, but the very fact that He spoke of His death disturbed them greatly.
As He approached Jerusalem for the last time during the days of His flesh, Jesus once again spoke of His sacrifice. “As Jesus was going up to Jerusalem, he took the twelve disciples aside, and on the way he said to them, ‘See, we are going up to Jerusalem. And the Son of Man will be delivered over to the chief priests and scribes, and they will condemn him to death and deliver him over to the Gentiles to be mocked and flogged and crucified, and he will be raised on the third day”” [MATTHEW 20:17-19].
This brings us to the text before us today. The Passion of the Master was but days away. He had gone with His disciples to the house of a man identified as Simon the Leper. Simon was a common name in Judah at this time; therefore, we cannot say with certainty who Simon might have been; however, it seems reasonable to conclude that the man had been healed by Jesus. Were this not the case, Jesus and the disciples would have been rendered ritually unclean by entering the house of someone with leprosy, and thus excluded from observing the Passover. Moreover, if Simon’s leprosy was still evident, he would not have been allowed to live near others. Therefore, it seems best to conclude that Jesus had cleansed Simon at some earlier date.
The information provided leads me to conclude that this dinner was hosted by a man whom Jesus had healed; the meal was his way of expressing gratitude for what Jesus had done. He likely knew Lazarus and his sisters, and he must surely have known that Jesus had raised Lazarus from the dead; therefore, he asked that they join in presenting the dinner. The fact that John specifically says that Lazarus “gave a dinner” and that Martha was serving [see JOHN 12:1, 2] would indicate that the four had united to present this meal in honour of Jesus.