Share Repurchase Shortcut

Can someone please explain the intuition behind this: If the after-tax yield on company funds used to repurchase shares, or the after-tax cost of borrowed funds used to repurchase shares, is greater than the earnings yield, EPS will fall as a result of the repurchase. If the after-tax yield on company funds used to repurchase shares, or the after-tax cost of borrowed funds used to repurchase shares, is less than earnings yield, EPS will rise as a result of the repurchase.

I don’t get how earnings yield and cost of funds used to repurchase related to each other.