רַ֛ק אַדְמַ֥ת הַכֹּהֲנִ֖ים לֹ֣א קָנָ֑ה כִּי֩ חֹ֨ק לַכֹּהֲנִ֜ים מֵאֵ֣ת פַּרְעֹ֗ה וְאָֽכְל֤וּ אֶת־חֻקָּם֙ אֲשֶׁ֨ר נָתַ֤ן לָהֶם֙ פַּרְעֹ֔ה עַל־כֵּ֕ן לֹ֥א מָכְר֖וּ אֶת־אַדְמָתָֽם׃
Only the land of the priests bought he not, for the priests had a portion from Pharaoh, and did eat their portion which Pharaoh gave them; wherefore they sold not their land.
Read kabbalistic (mystical) interpretation of Genesis 47:22: and classical mystical sources.