'Adi bin Hatim (May Allah be pleased with him) reported:
Messenger of Allah (ﷺ) said, "Guard yourselves against the Fire (of Hell) even if it be only with half a date-fruit (given in charity); and if you cannot afford even that, you should at least say a good word."

[Al-Bukhari and Muslim].

عن عدي بن حاتم رضي الله عنه قال‏:‏ قال رسول الله صلى الله عليه وسلم ‏ "‏اتقوا النار ولو بشق تمرة فمن لم يجد فبكلمة طيبة‏"‏ ‏(‏‏(‏متفق عليه‏)‏‏)‏ ‏.‏
Sunnah.com reference : Book 2, Hadith 13
Arabic/English book reference : Book 2, Hadith 693