Gita 04.04 explained
aparaṁ bhavato janma
paraṁ janma vivasvataḥ
katham etad vijānīyāṁ
tvam ādau proktavān iti
Word for word:
arjunaḥ uvāca — Arjuna said; aparam — junior; bhavataḥ — Your; janma — birth; param — superior; janma — birth; vivasvataḥ — of the sun-god; katham — how; etat — this; vijānīyām — shall I understand; tvam — You; ādau — in the beginning; proktavān — instructed; iti — thus.
Arjuna said: The sun-god Vivasvān is senior by birth to You. How am I to understand that in the beginning You instructed this science to him?
In previous chapter also Shri Krishna covers this in 3.31 & 3.32. Also in 4.39 & 4.40 Krishna said those who has faith is liberated, faithful will acquire knowledge and doubtful will be perished.
If there is logical question we should have intelligent answers and doubts should be clarified.