No small sin

 “I was completely opposed to Rabbi Kalischer on this subject. More than three or four times he wrote to me and sent me his books and pressured me to take a leading role in his movement to settle Eretz Yisroel, until he finally came to me and accused me of delaying the redemption. And I asked him to leave me alone on this matter, for what they consider a great mitzvah is in my eyes no small sin, and therefore it is impossible to reach common ground.” ( Rav Hirsch to Rabbi Yaakov Lipshitz, personal secretary of Rabbi Yitzchok Elchonon Spector, 1886, Shemesh Marpei, p. 216)