Terumah and Ma'aser and Earthquakes
The Prophet Eliyahu, of blessed memory, asked Rabbi Nehorai why earthquakes happen in Eretz Yisrael. The reply was because of the sin of failing to do the separating of terumah and the tithing of the maaser.
He based this on the apparent conflict between two passages:
"The eyes of the L-rd, your G-d, are constantly looking with care upon it (Eretz Yisrael)." (Devarim 11:12)
"He (G-d) gazes upon the earth and it trembles, touches the mountains and they erupt." (Tehillim 104:32)
How do we reconcile these two passages?
When Jews do the will of G-d and do their tithing as they should G-ds eyes "are constantly looking with care upon the Land" from the beginning of the year till the end of the year" (Devarim ibid.) and it suffers no harm. But when Jews fail to do the will of G-d and do not tithe as they should "He gazes upon the earth and it trembles." (Talmud Yerushalmi Berachot 9:2)