I was cast upon thee from the womb - Upon thy protection and care. This, too, is an argument for the divine interposition. He had been, as it were, thrown early in life upon the protecting care of God. In some special sense he had been more unprotected and defenseless than is common at that period of life, and he owed his preservation then entirely to God. This, too, may have passed through the mind of the Redeemer on the cross. In those sad and desolate moments he may have recalled the scenes of his early life - the events which had occurred in regard to him in his early years; the poverty of his mother, the manger, the persecution by Herod, the flight into Egypt, the return, the safety which he then enjoyed from persecution in a distant part of the land of Palestine, in the obscure and unknown village of Nazareth. This too may have occurred to his mind as a reason why God should interpose and deliver him from the dreadful darkness which had come over him now.
Thou art my God from my mother's belly - Thou hast been my God from my very childhood. He had loved God as such; be had obeyed him as such; he had trusted him as such; and he now pleads this as a reason why God should interpose for him.

I was cast upon thee from the womb: thou [art] my God from my mother's (f) belly.
(f) For unless God's providence preserves the infants, they would perish a thousand times in the mother's womb.

I was cast upon thee from the womb,.... Either by himself, trusting in God, hoping in him, and casting all the care of himself upon him; or by his parents, who knew the danger he was exposed to, and what schemes were laid to take away his life; and therefore did, in the use of all means they were directed to, commit him to the care and protection of God: the sense is, that the care of him was committed to God so early; and he took the care of him and gave full proof of it:
thou art my God from my mother's belly: God was his covenant God from everlasting, as he loved his human nature, chose it to the grace of union, and gave it a covenant subsistence; but he showed himself to be his God in time, and that very early, calling him from the womb, and making mention of his name from his mother's belly, and preserving him from danger in his infancy; and it was his covenant interest in God, which, though mentioned last, was the foundation of all his providential care of him and goodness to him. Now all these early appearances of the power and providence of God, on the behalf of Christ as man, are spoken of in opposition to the scoffs and flouts of his enemies about his trust in God, and deliverance by him, and to encourage his faith and confidence in him; as well as are so many reasons and arguments with God yet to be with him, help and assist him, as follows.