Midras Mazmur 119:19: Mekhilta DeRabbi Yishmael & Midrash Tehillim

Abraham called himself a stranger, viz. (Genesis 23:4) "A stranger and a sojourner am I with you." David called himself a stranger, viz. (Psalms 119:19) "I am a stranger in the land," and (I Chronicles 29:15) "For we are strangers before You and sojourners as all of our ancestors. As a shadow are our days upon the earth, without a prospect." And it is written (Psalms 39:13) "For a stranger am I with You, a sojourner as all of my ancestors."

I am a stranger in the land; do not hide your commandments from me. And just as David was a stranger, it is said that just as a convert today knows nothing of the Torah, so too the eyes of a person are open and he knows nothing of the Torah. And if David, who said all these psalms and songs, said "I am a stranger in the land and know nothing," how much more so are we who know nothing of the Torah? Therefore it is said, "I am a stranger in the land." And so it is written (1 Chronicles 29:15), "For we are strangers before You, and sojourners, as were all our fathers; our days on earth are like a shadow." This shadow passes over a person. And when are our days like a shadow? If we do not study and engage in the Torah. And our sages have taught us today that the day is short, the work is abundant, the laborers are lazy, the wages are high, and the owner of the house is pressed. Therefore it is said, "I am a stranger in the land; do not hide your commandments from me."