וַיֹּ֥אמֶר ל֖וֹ דָּוִ֑ד אִ֚ם עָבַ֣רְתָּ אִתִּ֔י וְהָיִ֥תָ עָלַ֖י לְמַשָּֽׂא׃
And David said unto him: ‘If thou passest on with me, then thou wilt be a burden unto Me;
Read kabbalistic (mystical) interpretation of II Samuel 15:33: and classical mystical sources.