לְאַֽהֲבָה֙ אֶת־יְהוָ֣ה אֱלֹהֶ֔יךָ לִשְׁמֹ֥עַ בְּקֹל֖וֹ וּלְדָבְקָה־ב֑וֹ כִּ֣י ה֤וּא חַיֶּ֙יךָ֙ וְאֹ֣רֶךְ יָמֶ֔יךָ לָשֶׁ֣בֶת עַל־הָאֲדָמָ֗ה אֲשֶׁר֩ נִשְׁבַּ֨ע יְהוָ֧ה לַאֲבֹתֶ֛יךָ לְאַבְרָהָ֛ם לְיִצְחָ֥ק וּֽלְיַעֲקֹ֖ב לָתֵ֥ת לָהֶֽם׃ (פ)
Miłując Wiekuistego, Boga twojego, słuchając głosu Jego, i lgnąc do Niego, - gdyż to jest życie twoje i przedłużeniem dni twoich, - abyś pozostał na ziemi, o której przysiągł Wiekuisty ojcom twoim, Abrahamowi, Ic'hakowi i Jakóbowi, iż ją odda im».
Sforno on Deuteronomy
ולדבקה בו, meaning that all of your activities during life on earth should be focused on giving glory to His name.
Or HaChaim on Deuteronomy
לאהבה את ה׳ אלוקיך, "to love the Lord your G'd, etc." This passage is a continuation of the thoughts in verse 19 "in order that you may live, you and your offspring." The purpose of this desire for life on this earth must be to learn to love G'd and to obey His commandments. When Moses concludes: "for He is your life, etc." Moses merely reflects that there cannot be a meaningful purpose in life on earth other than to cleave to G'd to the best of our abilities. This makes our life in this world a fitting prelude to our life in the celestial spheres., i.e. ארך ימים.
Haamek Davar on Deuteronomy
To obey Him. This refers to the in depth study and toil in Torah.