A bearded old man sits in profile, his head bowed and eyes cast downward, filling the left half of the panel. His long white beard flows over a heavy brown cloak, which envelops his shoulders and arm, painted with broad, textured strokes that reveal the wood grain beneath. A dark, fur-lined hat sits atop his head, its shadow merging with the deep browns of the background, while a few wisps of hair escape beneath its brim.

The man's face, illuminated from the upper left, glows with warm flesh tones against the muted, earthy palette that dominates the composition. The brushwork is loose and expressive, especially in the cloak and background, where swirling strokes suggest folds and depth without precise detail. His hands are barely indicated, one emerging from the cloak to rest near the lower edge of the panel, rendered with just a few quick lines and dabs of paint.

The background is an undefined, softly blended field of brown, which pushes the figure forward and creates a sense of intimacy and immediacy. Touches of lighter ochre and white highlight the man's beard and the trim of his garment, drawing attention to his contemplative expression. The composition is tightly framed, with the figure filling nearly the entire space and the edges of the panel visible at the sides.

Every detail, from the rough texture of the cloak to the delicate modeling of the face, is shaped by the artist's energetic, confident brushwork. Portrait of an Old Man (Possibly a Rabbi) was painted by Rembrandt in 1655. The Leiden Collection identifies this work as an oil sketch of an old man, and the title suggests the sitter may be a rabbi. Rembrandt creates a sense of introspection and dignity through the sitter's pose and the subtle play of light across his features.