There was a certain Israeli journalist who had extremely anti religious viewpoints. One time, his wife became ill and deperately needed an operation in the US. The problem was that he didn't have the money to pay for the operation. He was told to go to the Satmar Rebbe who was known for his extreme generosity [he wouldn't go to sleep at night if he had any extra money - he made sure to give it all away]. He obviously felt very uncomfortable doing that because of his stridently anti religious viewpoints and the publicity he gave them.
Nevertheless, when he arrived in the US, he went to the Rebbe and told him the situation. The Rebbe promptly gave him enough money to cover the operation, the recovery process and their stay in the US.
When he was on his way back to Israel, he first stopped by the Rebbe to thank him. The Rebbe said צא מכאן עוכר ישראל - Get out of here, you disgusting Jew.
Havdala. The Rebbe made a separation between doing chesed for a Jew and relating to a Jew when the chesed is no longer necessary. He felt that his job was to "rock" the guy, so he did so. But that had nothing to do with the chesed he was more than happy to do on his behalf.
[לדעת בארץ דרכך עמ' 158]
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There was once a tzadik and Baal Chesed named R' Avraham Shulman. Among other acts of chesed, he would accompany sick people to the US for medical treatment. One time, he accompanied a certain Rov to the US and went to the Satmar Rebbe to receive a bracha. The Rebbe said "You don't have any Rebbes in Eretz Yisrael that you come to me?" He instead gave him 500 dollars to help with the medical expenses.
R' Shulman left but started feeling guilty. He hadn't told the Rebbe that this Rov was a dayan whose salary was paid by Medinas Yisroel רח"ל. If the Rebbe had known that maybe he would not have given the money. So he went back in and told him the truth.
"What are you talking about", said the Rebbe, "I help every Jew, even non-religious Jews...." He then gave him another 100 dollars. [Chasdei Avraham P. 82]
Again - Havdala between chesed and differences in hashkafa.
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The Satmar Rebbe was an outspoken opponent of Agudas Yisrael. He didn't like that fact that they were members of the כנסת המינים - that heretical governmental body of evil doers and scoffers [in the Rebbes mind. I personally vote...:-)]. Rav Aharon Kotler was an outspoken supporter of the Aguda. They had a serious difference of opinion and they were both fire and brimstone people so it got heavy.
Yet, when Rav Aharon died, it was the Rebbe who tearfully eulogized him, mourning the loss of a great and unreplacable leader. [לדעת בארץ דרכך]
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ומענין לענין A story I once heard [it is only approximately and I don't have the source but ניכרים דברי אמת] - Someone once came to the Satmar Rebbe in a wheelchair, claimed he didn't have legs, told a sob story and asked for money. The Rebbe gave him a huge sum [I think it was 20k]. After the man left the Rebbe's room, he walked out of his wheelchair, healthier than ever... The people who observed this came into the Rebbe and cried that the man was a fake - he was really healthy. They wanted the Rebbe to get his money back and give it to the guy.
The Rebbe said "BARUCH HASHEM!!! He is really healthy. Has has legs. BARUCH HASHEM!!"
זכותו יגן עלינו....
Havdala.