Malbim: In man's initial formation, You oversaw him with the ultimate mercy and Chesed, even though he was not worthy of it. He did not serve Hashem yet! If so, it is proper that Your Chesed continue without ceasing, even if I am not worthy based on my deeds. Mercy refers to completing all the limbs of his body with ultimate mercy in each limb. Chesed refers to powers of intellect and understanding, so he will fathom [Hashem's] grandeur.

Rashi: They are from the days of Adam ha'Rishon. You said "b'Yom Achalcha Mimenu Mos Tamus" (Bereishis 2:17), and You gave to him a day of Yours, which is 1000 years.

Radak: At the time of my creation, I had Your mercy and Chesed in my mother's womb, and when I grew after leaving it. Since You raised me and brought me until here, it is proper that You have mercy on me, for I am Your handiwork, like Iyov said "Zechar Na Ki cha'Chomer Asisani" (10:9).