NIV 1 Timothy 3:15 if I am delayed, you will know how people ought to conduct themselves in God's household, which is the church of the living God, the pillar and foundation of the truth.
WH ἐὰν δὲ βραδύνω, ἵνα εἰδῇς πῶς δεῖ ἐν οἴκῳ θεοῦ ἀναστρέφεσθαι, ἥτις ἐστὶν ἐκκλησία θεοῦ ζῶντος, στύλος καὶ ἑδραίωμα τῆς ἀληθείας·
I see this is usually translated "pillar and foundation" or similar implying that the truth is supported (held up) by the assembly. The word "foundation" seems to suggest that the truth "rests on" the assembly. But to my mind this is entirely backward since the assembly rests on the truth. As Paul said:
NIV Romans 3:4
Not at all! Let God be true, and every human being a liar. As it is written: "So that you may be proved right when you speak and prevail when you judge."
Might the "pillar and foundation" be "the pillar and base"? In other words, the base rests on the ground (which is the foundation) and the pillar rests on the base and the truth is thus lifted up and put on display in the assembly. In other words, would one speak of the display of a bust resting on a "pillar and base" to enhance its beauty rather than to in some way be responsible for maintaining truth?
Ellicott uses "display" terminology: https://biblehub.com/commentaries/ellicott/1_timothy/3.htm