56 No less real were the tears He shed for Lazarus. The first question here is, What was there to weep for in the case of Lazarus? Not his death, for that was not unto death, but for the glory of God: for the Lord says, That sickness is not unto death, but for the glory of God, that the Son of God may be honoured through him. The death which was the cause of God's being glorified could not bring sorrow and tears. Nor was there any occasion for tears in His absence from Lazarus at the time of his death.
He says plainly, Lazarus is dead, and I rejoice for your sakes that I was not there, to the intent that you may believe. His absence then, which aided the Apostles' belief, was not the cause of His sorrow: for with the knowledge of Divine omniscience, He declared the death of the sick man from afar. We can find, then, no necessity for tears, yet He wept. And again I ask, To whom must we ascribe the weeping? To God, or the soul, or the body? The body, of itself, has no tears except those it sheds at the command of the sorrowing soul.
Far less can God have wept, for He was to be glorified in Lazarus. Nor is it reason to say His soul recalled Lazarus from the tomb: can a soul linked to a body, by the power of its command, call another soul back to the dead body from which it has departed? Can He grieve Who is about to be glorified? Can He weep Who is about to restore the dead to life? Tears are not for Him Who is about to give life, or grief for Him Who is about to receive glory. Yet He Who wept and grieved was also the Giver of life.
Source: On the Trinity (New Advent)