Musar su I Cronache 29:14

איש כמתנת ידו כברכת ה' אלוקיך אשר נתן לך . The two letters כ in front of the words כמתנת, כברכת, are a reminder that when we give a gift we should never feel that what we are giving away was ours in the first place, and that we therefore are truly generous. Whatever is at our disposal was given to us by G–d. David expressed this idea already very forcefully when he said (Chronicles I 29,14): כי ממך הכל ומידך נתנו לך, “For everything is from You, and it is Your gift that we have given to You.” The Torah alludes to this by not writing מתנת ידך, but כמתנת ידך instead.