Hadith 1620
Umar bin Khattab (RA) reported: I donated a pedigree horse in the path of Allah. Its possesser made it languish. I thought that he would sell it at a cheap price. I asked Allah's Messenger (ﷺ) about it, whereupon he said: Don't buy it and do not get back your charity, for one who gets back the charity is like a dog who swallows its vomit.
Hadith 1620
Zaid bin Aslam reported on the authority of his father that 'Umar (RA) donated a horse in the path of Allah. He found that it had languished in the hand of its possessor, and he was a man of meagre resources He (Hadrat 'Umar) intended to buy it. He came to Allah's Messenger (ﷺ) and made a mention of that to him, whereupon he said: Don't buy that even if you get it for a dirham for he who gets back the charity is like a dog which swallows its vomit.
Hadith 1851
The same tradition has been transmitted by a different chain of narrators.
Hadith 2754
حَدَّثَنِي
الْحَسَنُ بْنُ عَلِيٍّ الْحُلْوَانِيُّ ،
وَمُحَمَّدُ بْنُ سَهْلٍ التَّمِيمِيُّ وَاللَّفْظُ لِحَسَنٍ ، حَدَّثَنَا
ابْنُ أَبِي مَرْيَمَ ، حَدَّثَنَا
أَبُو غَسَّانَ ، حَدَّثَنِي
زَيْدُ بْنُ أَسْلَمَ ، عَنْ
أَبِيهِ ، عَنْ
عُمَرَ بْنِ الْخَطَّابِ ، أَنَّهُ قَالَ : قَدِمَ عَلَى رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ بِسَبْيٍ ، فَإِذَا امْرَأَةٌ مِنَ السَّبْيِ تَبْتَغِي إِذَا وَجَدَتْ صَبِيًّا فِي السَّبْيِ أَخَذَتْهُ ، فَأَلْصَقَتْهُ بِبَطْنِهَا وَأَرْضَعَتْهُ ، فَقَالَ لَنَا رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ : " أَتَرَوْنَ هَذِهِ الْمَرْأَةَ طَارِحَةً وَلَدَهَا فِي النَّارِ ؟ " ، قُلْنَا " لَا وَاللَّهِ وَهِيَ تَقْدِرُ عَلَى أَنْ لَا تَطْرَحَهُ ، فَقَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ : " لَلَّهُ أَرْحَمُ بِعِبَادِهِ مِنْ هَذِهِ بِوَلَدِهَا " .
'Umar bin Khattab reported that there were brought some prisoners to Allah's Messenger (ﷺ) amongst whom there was also a woman, who was searching (for someone) and when she found a child amongst the prisoners, she took hold of it, pressed it against her chest and provided it suck. Thereupon Allah's Messenger (ﷺ) said: Do you think this woman would ever afford to throw her child in the Fire? We said: By Allah, so far as it lies in her power, she would never throw the child in Fire. 'Thereupon Allah's Messenger (ﷺ) said: Allah is more kind to His servants than this woman is to her child.