Parashas Naso · Passuk 5:12
Speak to the Israelite people and say to them:Regarding anyonedanyone More precisely, “anyone, without exception,….” whose wife has gone astray and broken faith with him,
Chabad.org — English translation + Rashi
Source: Sotah 2a.
English: “Speak to the children of Israel” — R’ Yochanan said: Why was the section of the sotah placed next to the section of terumos and maasros? To tell you that anyone who has terumos and maasros and does not give them to the kohen will eventually come to the ordeal of a suspected wife.
In context: The juxtaposition is midrashically causal: neglect of the priestly gifts leads to domestic suspicion and the bitter-water ordeal.
Custom
Chazal link the withholding of terumah to the eventual need for the sotah ritual.