TgO Gen48:4 :וְאִתֵין יָת ארעא הָדָא לִבנָך בָתְרָך אַחסָנַת עָלַם‏ : I shall give this land to your son after you as an eternal holding
See the entire entry for ˁālam, ˁālmā n.m. eternity; world