What is the ruling on lying to a sick grandmother that her two sons have reconciled, even though the reconciliation has not taken place, in order to reassure her in her illness?

Lying is forbidden, but the Shariah has granted concessions for it in warfare, in reconciling disputes between people, and between spouses. The brother can use allusions and circumlocutions to please his mother. If pleasing her is not possible except through lying, then lying is permissible to the extent of the need, and the ruling on the lie depends on the ruling of the intended outcome.