It was narrated from Abu Hurairah that the Messenger of Allah (ﷺ) said: "The poor man (Miskin) is not the one who leaves if you give him a morsel or two, or a date or two." They said: "Then who is the Miskin, O Messenger of Allah?" He said: "The one who does not possess independence of means, and the people do not know of his need, so that they could give him charity."
Source: sunnah.com
Other translations
Arabic
أَخْبَرَنَا نَصْرُ بْنُ عَلِيٍّ، قَالَ حَدَّثَنَا عَبْدُ الأَعْلَى، قَالَ حَدَّثَنَا مَعْمَرٌ، عَنِ الزُّهْرِيِّ، عَنْ أَبِي سَلَمَةَ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " لَيْسَ الْمِسْكِينُ الَّذِي تَرُدُّهُ الأُكْلَةُ وَالأُكْلَتَانِ وَالتَّمْرَةُ وَالتَّمْرَتَانِ " . قَالُوا فَمَا الْمِسْكِينُ يَا رَسُولَ اللَّهِ قَالَ " الَّذِي لاَ يَجِدُ غِنًى وَلاَ يَعْلَمُ النَّاسُ حَاجَتَهُ فَيُتَصَدَّقَ عَلَيْهِ " .
sunnah.com