Sonny Bermejo is a brilliant math teacher in a private university in Quezon City and gets a monthly salary of P25,000. Another school in the city offers him a higher salary of P30,000 a month. Sonny Bermejo makes a verbal commitment to the other school's principal, "Sure, I'll join your school next month." But when Sonny Bermejo submits his resignation to his present employer, its Principal Mr. Carlo Lorenzo requests him to stay and offers P30,000 basic salary plus P5,000 transportation and clothing allowance.

Should Sonny Bermejo take back his resignation? Why?