Major League Baseball has cautioned players against writing on their caps after several Giants pitchers wrote Bible verses on their Pride Night hats during a game Friday.

“The writing on the cap violates our rules, and consistent with normal practice, we have warned the players about future violations,” the league said in a statement.

The Giants—the first MLB team to incorporate Pride elements into their uniforms—wore hats with rainbow colors on the logo for Friday’s game against the Cubs. Starting pitcher Landen Roupp and relievers JT Brubaker and Ryan Walker wrote the Bible verse “Genesis 9:11–16” on their caps next to the logo, while Sam Hentges wore the standard Giants cap without the rainbow colors. All four appeared in the game.

The verses referenced rainbows, stating that God will never flood the earth and that a rainbow will be a symbol of that promise.

Roupp told reporters after the game that he meant “no hate” with his actions. Asked what he would say to anyone who took offense with it, Roupp said: