דניאל, פרק י׳, פסוק ג׳

Daniel engages in a period of mourning and self-denial lasting three full weeks. Rather than undertaking a total fast, he chooses to live in absolute simplicity, sustaining himself on the bare minimum and entirely avoiding physical pleasures and delicacies [ביאור שטיינזלץ].

The primary approach among commentators is that he avoids high-quality, refined bread made from fine flour. [רש״י] notes that the description of this bread indicates it is exceptionally clean and pure. Instead of partaking in such fine baked goods, Daniel consumes only cheap, basic bread [ביאור שטיינזלץ]. Even at night, when he breaks his daily fast, he maintains this strict discipline, carefully avoiding refined bread and wine [מלבי״ם].

Alongside his restriction from meat and wine, Daniel refrains from anointing his body with oil, denying himself a common luxury usually enjoyed for physical comfort [מצודת דוד, ביאור שטיינזלץ]. He maintains this rigorous lifestyle without interruption until the entire three-week period comes to a complete close [מצודת ציון, ביאור שטיינזלץ].