5 “But Mary was she who anointed the Lord with ointment, and wiped His feet with her hair, whose brother Lazarus was sick. Therefore his sisters sent unto Him, saying.” We now understand whither it was they sent, namely, where the Lord was; for He was away, as you know, beyond the Jordan. They sent messengers to the Lord to tell Him that their brother was ill. He delayed to heal, that He might be able to raise to life. But what was the message sent by his sisters? “Lord, behold, he whom You love is sick.”
They did not say, Come; for the intimation was all that was needed for one who loved. They did not venture to say, Come and heal him: they ventured not to say, Command there, and it shall be done here. And why not so with them, if on these very grounds the centurion's faith was commended? For he said, “I am not worthy that You should enter under my roof; but speak the word only, and my servant shall be healed.” No such words said these women, but only, “Lord, behold, he whom You love is sick.”
It is enough that You know; for You are not one that loves and forsakes. But says some one, How could a sinner be represented by Lazarus, and be so loved by the Lord? Let him listen to Him, when He says, “I came not to call the righteous, but sinners.” For had not God loved sinners, He would not have come down from heaven to earth.
Source: Tractates on the Gospel of John (New Advent)