TgO Ex12:13 :וִיהֵי דְמָא לְכוֹן לְאָת עַל בָתַיָא‏ : let the blood be a mark for you on the houses
See the entire entry for ˀāṯ, ˀāṯā n.f. sign

TgO Ex12:13 :וְאִחזֵי יָת דְמָא וְאֵיחוּס עְלֵיכוֹן‏ : I will see the blood and take pity on you
See the entire entry for ḥws vb. to have pity on