Farewell at Dawn (1956)

Ahmad is an air-force fighter who lives with his rich father who wants him to marry partner's daughter; but he falls in love with Zainab, the poor distant relative, and marries her despite of his father's disapproval. Soon, Ahmad leaves to serve in the Palestine War leaving his wife behind, and he becomes missing in action. She later marries her kind and loving neighbor before finding out that Ahmad wasn't killed in action and that he managed to escape.