In Exo 6:28-30 the thread of the history, which was broken off at Exo 6:12, is again resumed. דִּבֶּר בְּיֹום, on the day, i.e., at the time, when God spake. יֹום is the construct state before an entire clause, which is governed by it without a relative particle, as in Lev 7:35; 1Sa 25:15 (vid., Ewald, §286i).