Samyutta Nikaya
During meditation, one may contemplate the seven Factors of Enlightenment as well as on their antithesis, the Five Hindrances (sensual pleasure, ill-will, sloth-torpor, restlessness-worry, doubt). In addition, one Samyutta Nikaya sutta identifies developing each of the enlightenment factors accompanied by each of the four brahma viharas (lovingkindness, compassion, sympathetic joy, equanimity).