Lexical Definition

‎טֻחָה‎ ṭuchâh (too-khaw') inner parts ^H:N-F
from ‎טָחָה‎ (or ‎טוּחַ‎) in the sense of overlaying

inward parts.

• (in the plural only) the kidneys (as being covered)
• hence (figuratively) the inmost thought

1) inner regions, hidden recesses, inward parts

Brown-Driver-Briggs

‎טֻחוֺת‎ noun feminine plural inward parts (as covered over, concealed) — ‎טֻחוֺת‎ of seat of faithfulness, ‎׳‎‎אֱמֶת חָפַצְתָּ בַּטּ‎ Ps 51:8* faithfulness thou desirest in the inward parts, i.e. in the heart (|| ‎סָתֻם‎); of seat of wisdom ‎חָכְמָה‎ ‎׳‎‎מִי שָׁת בַּטּ‎ Job 38:36 (|| ‎שֶׂכְוִי‎ q. v.); from context this can hardly = heart of man (kidneys, 'reins,' ᵑ7, Jewish interpretations, see NHWB^{ii, 144} and others), but is rather cloud-layers (as dark, hidden spaces, see Di VB); their 'wisdom' appears in their obedience to natural law.

Brown-Driver-Briggs References