דברים טו, ח : כ ִּי -פָּתֹחַ ת ִּפְת ַח אֶת- ֹולךְדָּי
"You shall surely open (posach tiftach) your hand to him ..." (15:8).
The double 'Pey' denotes that one should open, not only one's hand, says the Baal haTurim, but also one's mouth, to offer him a kind word.
Alternatively, if the poor man needs bread, give him bread, if he needs sweets, then give him sweets - open your hand to him in every way that assists him.
Alternatively, if he is embarrassed to come to you, you bring it to him.
Alternatively, the Torah writes a double expression in all matters that concern Tzedakah - "Posach tiftach", "Nasan titein", Ha'anek Ta'anik" (when an Eved Ivri he goes free). The message comes across loud and clear - there is no limit to giving; give and give again!
