This verb is rendered in a variety of ways in the New Testament, as give or furnish, present, provide, assist, commend. The original meaning is to place beside, and so commend to the attention. Hence, to set before the mind; present, shew.
Infallible proofs (τεκμηρίοις)
The word is akin to τέκμαρ, a fixed boundary, goal, end; and hence a fixed or sure sign or token. The Rev. omits infallible, probably assuming that a proof implies certainty.
Being seen (ὀπτανόμενος)
Only here in New Testament. Rev., appearing.
Forty days (δι' ἡμερῶν τεσσεράκοντα)
Lit., “through forty days.” Rev., by the space of. The only passage where the interval between the resurrection and the ascension is given.