Umar bin Khattab reported,
The Messenger of Allah ﷺ commanded us one day to give in charity, and it happened to coincide with a time when I had some wealth. I said to myself, "Today I shall outdo Abu Bakr, if ever I am to outdo him." So I brought half of my wealth.The Messenger of Allah ﷺ asked, "What have you left for your family?"I replied, "The same amount."Then Abu Bakr 
came with everything he had. The Messenger of Allah ﷺ asked him, "What have you left for your family?"He answered, "I have left for them Allah and His Messenger."I said, "I will never compete with you in anything again!"
Azami 4081
Hasanعن عمر بن الخطاب قال
أمرنا رسول الله ﷺ يوما أن نتصدق فوافق ذلك مالا عندي، فقلت اليوم أسبق أبا بكر إن سبقته يوما فجئت بنصف مالي. فقال رسول الله ﷺ: ما أبقيت لأهلك؟ قلت: مثله. قال: وأتى أبو بكر رضي الله عنه بكل ما عنده، فقال له رسول الله ﷺ: ما أبقيت لأهلك؟ قال: أبقيت لهم الله ورسوله. قلت: لا أسابقك إلى شيء أبدا!
Abu Dawud (1678) and Tirmidhi (3675) both narrated it from the hadith of Fadl bin Dukayn, who said, "Hisham bin Saad narrated to us, from Zayd bin Aslam, from his father," and he related it. Tirmidhi said, "hasan sahih."Hakim also narrated it through this same route (414/1) and said, "sahih according to the criterion of Muslim."I say, it is as he said, and its isnad is hasan due to the criticism directed at Hisham bin Saad Madani. Although he is among the narrators relied upon by Muslim, Ibn Main, Nasai, and others criticized him, while other scholars accepted him, and he is hasan al-hadith.Bayhaqi, may Allah have mercy on him, said, "His statement ﷺ, 'The best charity is that given out of surplus wealth,' and his statement when asked about the best charity, 'the utmost effort of one who has little,' differ only according to the differing conditions of people in their patience with hardship and poverty, and their contentment with the least sufficiency."Then he narrated the hadith of this chapter through the route of Abu Dawud.