הַפֹּרְטִ֖ים עַל־פִּ֣י הַנָּ֑בֶל כְּדָוִ֕יד חָשְׁב֥וּ לָהֶ֖ם כְּלֵי־שִֽׁיר׃
That thrum on the psaltery, That devise for themselves instruments of music, like David;
Read kabbalistic (mystical) interpretation of Amos 6:5: and classical mystical sources.