As a boy, the songs and chants Mahler would have heard in the synagogue may well have influenced his predilection to use certain melancholic melodic shapes and bitter-sweet tonalities.
Mahler's Origins: A "Sonic Goulash"
The turn had a long and deep significance for Mahler that dates back to his earliest musical memories. In the synagogue, he would have heard the turn frequently as a ornament in the chanting of the Torah: for instance, in the cantillation called gershayim. He would probably have even sung it while reading the portion assigned to him for his bar mitzvah.