And yet (καιτο). Old Greek compound particle (κα το). In the N.T. twice only, once with finite verb as here, once with the participle (Hebrews 4:3).

Without witness (αμαρτυρον). Old adjective (α privative and μαρτυς, witness), only here in the N.T.

Left (αφηκεν). First aorist active (κ aorist indicative of αφιημ).

In that he did good (αγαθουργων). Present active causal participle of αγαθουργεω, late and rare verb (also αγαθοεργεω 1 Timothy 6:18), reading of the oldest MSS. here for αγαθοποιεω, to do good. Note two other causal participles here parallel with αγαθουργων, viz., διδους ("giving you") present active of διδωμι, εμπιπλων ("filling") present active of εμπιμπλαω (late form of εμπιμπλημ). This witness to God (his doing good, giving rains and fruitful seasons, filling your hearts with food and gladness) they could receive without the help of the Old Testament revelation (Romans 1:20). Zeus was regarded as the god of rain (Jupiter Pluvius) and Paul claims the rain and the fruitful (καρποφορουσ, καρπος, and φερω, fruit bearing, old word, here alone in N.T.) seasons as coming from God. Lycaonia was often dry and it would be an appropriate item. "Mercury, as the God of merchandise, was also the dispenser of food" (Vincent). Paul does not talk about laws of nature as if they governed themselves, but he sees the living God "behind the drama of the physical world" (Furneaux). These simple country people could grasp his ideas as he claims everything for the one true God.

Gladness (ευφροσυνης). Old word from ευφρων (ευ and φρην), good cheer. In the N.T. only Acts 2:28 and here. Cheerfulness should be our normal attitude when we consider God's goodness. Paul does not here mention Christ because he had the single definite purpose to dissuade them from worshipping Barnabas and himself.