|ט וְכָל-תְּרוּמָה לְכָל-קָדְשֵׁי בְנֵי-יִשְׂרָאֵל אֲשֶׁר-יַקְרִיבוּ לַכֹּהֵן–לוֹ יִהְיֶה.||9 And every heave-offering of all the holy things of the children of Israel, which they present unto the priest, shall be his.|
|י וְאִישׁ אֶת-קֳדָשָׁיו לוֹ יִהְיוּ אִישׁ אֲשֶׁר יִתֵּן לַכֹּהֵן לוֹ יִהְיֶה.||10 And every man’s hallowed things shall be his: whatsoever any man giveth the priest, it shall be his.|
I would like to humbly suggest, that based on the definition of stealing, above from Bikkurim, it seems that chessed and stealing are polar opposites of one another (not only because one is nice and one is not nice). Stealing is gaining pleasure from something that isn’t yours, which belongs to someone else; Chessed is taking what IS rightfully yours and voluntarily giving it to someone else. One is taking something you don’t own, and the other is giving something you do own.
Finally, another aspect of becoming a mamlechet kohanim v’goy kadosh, is cleaving to role models who exemplify righteousness and proper values, which brings us to another Moab ancestor: Lot was the incestuous grandfather of Moav (the guy), and an ancestor of Ruth. Lot left the tent of Avraham Avinu to live in the most grotesque city of its time, in Sedom. He left the greatest role model of chessed to chase wealth (see B’reishit 13:10, describing Sedom’s saturated fields) and to be with the licentious people of Sedom. Ruth, by contrast, was royalty – a descendant of Eglon and Balak. She left luxury so that she could cleave to Naomi, because she realized that being with Naomi and learning from her was (a) the right thing to do, and (b) far more valuable than material wealth.
By clinging to special individuals with character traits befitting a mamlechet kohanim, we equip ourselves to strive for righteousness, and ensure that those values get passed to the next generation.
In sum, Bikkurim teaches the importance of appropriating ownership properly; Ruth teaches the importance of chessed, sacrificing ourselves and our material possessions to benefit others, and the middos necessary to be worthy of receiving the Torah.