Provide a Reason for the Discount

Customers should believe that your discount is temporary so that this lower price doesn't become a new permanent reference price.

Overview

Explain why you’re offering a discount.

Otherwise, your regular price will seem more more expensive when it returns. Customers will compare your regular with the discounted price. Temporary discounts will impede this mental process.

Plus, customers are more likely to pounce on a temporary discount. Perhaps you could mention a “clearance” sale. Or you could refer to supplier price cuts:

[some stores] often convey the message that additional cost savings they are able to obtain from suppliers are being passed on to customers... presumably to minimize the negative effects of promotions (Mazumdar, Raj, & Sinha, 2005, p. 88)

Mazumdar, T., Raj, S. P., & Sinha, I. (2005). Reference price research: Review and propositions. Journal of marketing, 69(4), 84-102.