TgO Deut33:19 :נִכסֵי עַמְמַיָא יֵיכְלוּן וְסִימָן דְמִיטַמרָן בְחָלָא יִתגַליָן לְהוֹן‏ : they shall consume the property of the gentiles and even treasures hidden in the sand will be revealed to them
See the entire entry for sīmāh, sīmat, sīmṯā n.f. treasure; placement