Is it sufficient for a traveler to pray Isha combining it and shortening it, if he enters his city after Maghrib and prays in the mosques, or must he repeat the prayer?

Upon the traveler's arrival in his hometown, the concessions for travel cease, and he is obligated to complete the prayer and perform each prayer at its appointed time. Whoever combined and shortened prayers after his arrival must repeat the 'Isha' prayer in full at its appointed time, whether he prayed it in the mosque or at home.