אַתָּ֤ה יְהוָ֗ה לֹא־תִכְלָ֣א רַחֲמֶ֣יךָ מִמֶּ֑נִּי חַסְדְּךָ֥ וַ֝אֲמִתְּךָ֗ תָּמִ֥יד יִצְּרֽוּנִי׃
Thou, O LORD, wilt not withhold Thy compassions from me; let Thy mercy and Thy truth continually preserve me.
Read midrashic interpretation of Psalms 40:12: and classical rabbinic exegesis.