A.T. Robertson Commentary Acts 7:3

"and said unto him, Get thee out of thy land, and from thy kindred, and come into the land which I shall show thee." — Acts 7:3 (ASV)

Which I shall shew thee (ην αν σο δειξω). Indefinite relative clause with αν and the aorist active subjunctive (same form in first person singular as the future active indicative). Abraham followed on as God led him.